Art of casting pipes.



E. A. OUSTER. ART OF CASTING PIPES. APPLICATION FILED APR. "I, 1908.

906,204. I Patented Dec. 8,1908.

Twi a Lamas 4 3/7 a 1 V 2 A! w flvg gie EDGAR ALAN CUSTER, OF PHILADELPHIA. PENNSYLVANIA.

ART OF CASTING PIPES.

Specification of Letters Patent.

Patented Dec. 8, 1908.

Application filed April 7, 1908. Serial No. 125,672.

To all whom it may concern:

Be it known that I, EDGAR ALAN CUsTER, a citizen of the United States, residing at the city of'Philadelphia, in the county of Phila delphia and State of Pennsylvania, have invented certain new and useful Improve ments in the Art of Casting Pipes, of which the following is a specification.

My lIl'.GI1lLIl0]1 has relation to the art of casting metal structures, such as pipe for soil, water and gas purposes; and in such connection it relates to the production of homogeneous cast structures definitively soft or hard or tough, as desired, without particular consideration of the constituency of the iron forms, free or graphitic carbon and combined carbon. The amount of graphitic carbon present in iron depends upon the rate at which it is cooled. Further gra hitic carbon when molten iron is cooled s owly,

tends to segregate before the iron reaches the point at which it sets. Graphitic carbon forms very quickly and when the iron is cooled the free carbon diuides into two forms, graphitic and annealing. The difference between the two is simply a difierence in form,

because both have the same chemical characteristics, which demonstrates thatif molten iron is suddenly chilled to the point at which it sets, the formation of graphitic car 5bon in the iron is prevented and consequently all or nearly all the carbon exists in a combined state. This is'equally true in respect to the action of sulfur and phosphorus in the iron and consequently segre- 0 gation of these elements is prevented in the same said manner. The formation of annealing carbon in iron and of carbid carbon begins after the iron has passed the setting point and such'action can only take place Whenthe iron is permitted to cool normally,

so that if a structure be cast, as a pi e, in

' the defined manner, that is, chilled su denly from the molten state to the point at which it sets, and be then allowed to cool slowly at normal atmospheric temperature or at an established falling temperature, undesirable actions, as segregation and formation of graphitic carbon are preTented and desirable actions, as formation of annealing carbon and'carbid carbon regularly begin. These actions produce with certainty a thoroughly homogeneous product with such changed molecular conditions as to give either a soft or hard or tough product, as may be preferred.

' My invention broadly considered, consists in subjecting iron to the influence of heat in a furnace to bring to a molten state, then pouring into a permanent mold under existing conditions to chill suddenly to a setting point of the molten metal and then removln to permit the cast structure to then codl gradually to thereby derive a resultant homogeneous cast structure.

My invention as above defined will be more fully understood in connection with the accompanying drawing illustrating diagrammatically 'a lant, for carrying into effeet the method ol my present inzention.

Referring to the drawing, 1 is a cupola or other type of furnace for bringing the metal, as iron, into a molten state.

The furnace 1, is provided with a discharge spout 2, below which is preferably arranged a pouring ladle 3, pivotally supported from standards 4. Beneath the ladle 3, is located a mold 5, of a type of Letters Patent No. 887,070 granted to me under date of May 12th, 1908,! to which as to structural arrangement and the manner of operating recourse may be had; and also to my ap lication Serial No. 421,054 filed March 14t 1908,

showing such type of mold, but arranged in series upon a turntable for carrying out economica y and expeditiously the production of pipe according to the described method of my said invention.

The temperature of the molten iron as it leaves the cupola or other furnace 1, ranges between 2000 and 2800 Fahrenheit and in passing therefrom to the pouring ladle 3, the tern erature is not materially changed or mo ed. The instant, however, the pourings from the ladle 3, enter the interior of the mold 5, around a perforated or other composition core there is efiected a violent or sudden change on the molten mass due to the difference in maintained temperature between the permanent mold and ourcd metal. This results in reventing through the sudden chilling of tlie molten metal to the oint of setting of the formation of grap 'tic carbon in the iron structure, because all or nearly all the carbon is held in a combined state as segregation only occurs elements free to move.

carbon. action takes chilling of a cast iron structure to while the iron is in amolten condition. This is equally true in respect to the action of sulfur and phosphorus on the iron. From the period when the ironis set follows the formation of an annealing carbon and carbid place during the period of gradual cooling 0 .the iron in its structural orm. In further explanation of essential features of my defined method, in a casting, such as a thin pipe, in an ordina sand mold about a minute is required to coo themolten iron to the point at which the pi e sets. It is during this period detrimenta effects on the cast iron are sulfur and carbon carbon is formed. ing this period is in segregate and graphitic- The iron, however, dura liquid state, with all its Once the casting is set segregation ceases and the carbon remaining begins its beneficent action. The iron loses its heat at a normal rate and annealing and carbid carbon are formed, which improves the quality of the metal. Therefore, if the molten iron be swiftly poured into a permanent iron m old it will very quickly set by chilling suddeply and any evil eflects will thereby be appreciably reduced, in fact, to such an extent that the impurities the iron contained will be held in the position 00- cupied, while in the molten state. Further more, the evil effects of sulfur and phosphorus in the iron are reduced to a minimum, since they are in practically an atomic condition distributed uniformly throughout the subsequent castin If the cast structure is set by sudden c illing and the structure is then allowed to cool normally, practice has demonstrated that ideal conditions exist in the resultant product. Moreover, a point of extreme hardness is purely a mechanical action, and the point to which sudden chilling is carried can be determined to an absolute certainty by the said method with some regard to the constituency of the iron used, without fear of producing a ipe with a chilled surface or one incapalile of bein readily machined, drilled or threaded.

The method of my said invention, as hereinbefore'described is not confined to pi e makin alone, as other types of castings Y the dehned steps thereof, 1n permanent iron molds can be eflectedina most satisfactory manner.

Having thus described the nature and ohproduced. Phosphorus,

1700 and 2200 jects of my invention what I claim as new and desire to secure by Letters Patent is: 1. The art of casting metal structures, which consists in chillin suddenly metal in a molten state to the point of setting in the structure and then cooling gradually at atmospheric temperature, substantially as and for the purposes described.

2. The art of casting metal structures, which consists in chilling suddenly molten iron to the point of setting in the structure and then cooling normally thereafter at atmos heric temperature, substantially as and for t e purposes described.

8. The art of casting metal structures, which consists in chilling suddenly molten iron to the point of setting in the structure and then cooling gradually at atmospheric temperature to prevent first undesirable actions as segregation and formation of graphitic carbon in the structure and second to permit of desirable actions as formation of annealing carbon and carbid-carbon therein,

substantially as and for; the purposes described.

4. The art of casting metal structures, which consists in maintaining molten metal at a temperature from 2000 to 2800 Fah., then quickly lowering the temperature of the same to from 1700 to 2200 Fah., by introducing into a permanent mold, and then permitting gradual lowering ofsuch temperature by removing the cast structure from the m'old, substantially as and for the purposes described.

5. The artof casting metal structures, which consists in maintaining molten metal at a temperature from 2000 to 2800 Fah., to hold the carbon of the same in solution, then quickly lowering such temperature between Fah., by introducing the metal into ermanent mold to maintain the carbon in a ely divided. state at a point at which the etal assumed form, and then permitting gradual lowering of the temperature of the metal and by the same the formation of annealing carbon and carbid-carbon, substantially as and for the purposes described;

In witness whereof, I have hereunto set my signature in the presence of two subscribing witnesses. v EDGAR ALAN CUSTER.

Witnesses:

WIL'HELM Voor, THOMAS M. SMITH. 

